Ambient temps

I just moved my BP's into tubs the hot spot is great at 92-94 degrees and the humidity is perfect, however the ambient temps are only rangeing from 75-80 is this too low ?

My UTH ranges from 86-88 with the aid of a thermostat. His ambient temp is about the same as yours. (his cold side sometimes gets as low as 70 at night in the winter. My Book (Ball Pythons by Colette Sutherland) Suggest hot spot at 80-85 for hatchlings, 85-90 for sub-adult to adult.Ambient air temps can range form high 70's to mid 80's. Then goes on to talk about watch your snakes behavior. If he spends all his time in his water bowl (excluding mites, wrong humidity) he's probably too hot. if he spends all day/night on the hot spot he may be too cool. (cool side) Personally my ball is happy with hots pot at 88 and ambient between 76-85. I personally avoid the hot spot reaching over 90 as they can get thermal burns if the temp spikes to more than 94 if allowed to stay on it. (same reason hot rocks are BAD)

You should be ok, but I wouldn't let the temps start getting below 75. I keep the ambient temp in my snake room around 78-82, depending on the time of day...

How can I boost the ambient temps should I suspend a heat over the tubs? I have already closed the vent in the room but it just gets a little cold in there.

You could get a second heat pad for each tub or get a small space heater for the room.
75-80 is fine, especially if you have a nice warm hot spot.

I like the idea of a space heater or a heating element./50-75 watt infrared (shielded from the snake of course)

I use a space heater for my snake room at night right now. It stays warm enough during the day without it since I have the a/c vent closed. If it gets too hot I just open the door and let some of the cooler air from the house circulate through...